<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        body{margin: 0}
        div{
            padding: 20px;
            margin: 20px;
            width: 100px;
            height: 100px;
            box-sizing: border-box;
        }
    </style>
</head>
<body>
    <div style="background: chartreuse">div1</div>
    <div style="background: aquamarine">div2</div>
    <div style="background: cadetblue">div3</div>
    <div style="background: brown">div4</div>
    <div style="background: lawngreen">div5</div>
    <div style="height: 20px;background: red;width: calc(100% - 40px);"></div>
</body>
</html>